Aerosol package

ABSTRACT

An aerosol package includes a rigid container having a dispensing valve and a collapsible flexible container inside of this rigid container and internally fluid-connected to its valve, the flexible container containing an extrudable liquid product in which a liquified compressed gas is intimately widely dispersed or dissolved. The package features a liquified compressed gas propellant in the rigid container on the outside of the flexible container and having a vapor pressure greater than that of the product&#39;&#39;s liquified gas as it is dispersed or dissolved in the product. Therefore, when the product is dispensed through the valve, this propellant continuously maintains the product under compression, through its flexible container, to a degree preventing the formation of a vapor phase in the product while the latter is extruding under the pressure of the propellant. The result is that the product&#39;&#39;s gas remains intimately widely dispersed or dissolved in the liquid product until exposed to the atmosphere, at which time this gas converts to its vapor phase to provide an expanded product that is always of the same density until the product is completely forced from its container.

United States Patent [1 1 Laauwe AEROSOL PACKAGE [76] Inventor: RobertH. Laauwe, 237 Ridge Rd.,

- Franklin Lakes, NJ. 07417 22 Filed: July 10, 1972 211 Appl. No.:270,560

52 U.S.Cl. 222/94 51 Int. Cl B65d 35/24 [58] Field of Search... 222/94,135, 386.5, 95, 389;

[56] I References Cited UNITED STATES PATENTS Primary ExaminerStanley H.Tollberg Attorney, Agent, or F irm- Kenyon & Kenyon, Reilly,

Carr & Chapin 57 ABSTRACT An aerosol package includes a rigid containerhaving a [451 Jan. 29, 1974 dispensing valve and a collapsible flexiblecontainer inside of this rigid container and internally fluidconnectedto its valve, the flexible'container containing an extrudable liquidproduct in which a liquified compressed gas is intimately widelydispersed or dissolved. The package features a liquified compressed gaspropellant in the rigid container on the outside of the flexiblecontainer and having a vapor pressure greater than that of the productsliquified gas as it is dispersed or dissolved in the product. Therefore,when the product is dispensed through the valve, this propellantcontinuously maintains the product under compression, through itsflexible container, to a degree preventing the formation of a vaporphase in the product while the latter is extruding under the pressure ofthe propellant. The result is that the products gas remains intimatelywidely dispersed or dissolved in the liquid product until exposed to theatmosphere, at which time this gas converts to its vapor phase toprovide an expanded product that is always of the same density until theproduct is completely forced from its container.

} 6 Claims, 3 Drawing Figures PATENTED 3. 788 52 l SHEET 2 IF 2 Thisinvention relates to aerosol packages, and it particularly concerns suchpackages when containing a liquid product in which a liquifiedcompressed gas is intimately dispersed or dissolved.

' For example only, aerosol packages of the shampoo, hair coloring andshaving cream type contain formulations which are usually oil-in-watertype emulsions, with the liquified compressed gas intimately dispersedin. the water solution. When the emulsion is discharged to theatmosphere, evaporation of the liquified gas to its vapor phase causes.the development of foam. In the case of hair coloring formulations, thepackage may contain a collapsible flexible container containing a liquidperoxide solution and have a codispensing valve having two inletsrespectively connected to the two liquids. The liquified gas inthe haircoloring formulation acts as a propellant to both produce a foam and todischarge the formulation throughthis valve, and also to apply extrusionpressure. to collapse the flexible container so. that.its contents aresimultaneously discharged, thevalve being designed to proportion the twoliquids as required to produce the desired hair coloring effect. V I I 1DESCRIPTION OF THE PRIOR ART A major partjiof the prior art is disclosedeffectively by the text Aei-osol: Science and Technology, edited by H.R. Shepherd, and published in 196 l by the .Interscience Publishers, IncNew York, New York. The

force necessary to extrude or eject the product from v the packagecontainer; and second, after the product has. been extruded into theatmosphere, this propellant or.er ratic discharge is obtained. Thischanging density is annoying in the case of shampoo and shaving creamformulations, as examples, but itmay be disastrous in the case of acodispensing package where the two products in the can must be dispensedwith rather exact proportioning of the two.

Shampoos and shaving cream formulations are usually oil-in-water typeemulsions, with the required compressed gas propellant intimatelydispersed in the water solution; and in the case of this type ofproduct, the prior art has provided no adequate solution to the aboveproblems insofar as is known. In the case of certain codispensingpackages, such as hair coloring packages, the only solution so far knownhas been to make the package in the form of a one-shot applicationpackage designed for a single usage as contrasted to a series ofone-shot applications extending over a long time period. It isunderstood that another possibility might be to use a hair coloringpackage of larger size but actuated'by professional hairdressers whofrom experience understand the varying hair color effects that will beobtained as the foam density changes and apply the coloring to differentcustomers. This latter practice is unsuited for use by individuals,because after the initial coloring effect is obtained, further touch-upapplications are unpredictable because different coloring effectsareobtained.

As an incidental annoyance, common to all prior art aerosol packages,the package must be operated only in a mainly upright condition. This isbecause there is a=vapor space above the product containing theliquified compressed gas propellant, so that when the package can isinverted, only vapor is ejected with no ejection of the desired product.

The prior art has suggested overcoming certain of the I foregoingunsatisfactory characteristics by using an undergoes an almostinstantaneous flash evaporation or conversion to .its vapor phaseintended to leave the product in a predetermined physical form; I a

' Her'etofore, such a package has comprised a rigid container which isusually a metal can, provided with an aerosol valve connecting with astandpipe inside of the can, with the latter containing the product inwhich the liquified compressed gas propellant is intimately dispersed ordissolved. As previously indicated, shampoo, hair coloring and shavingcream aerosol packages are examples.

Ordinarily, the user of such a package actuates it so as to dischargeonly a small percent .of its contents per day, or otherwise atintermittent intervals over a long time period. With prior art packages,the physical charcannot radially collapse, the bag collapsing only in ah acteristics, such as overrun and density in the case of aerosolpackage system sold under the trademark Sepro by the Continental CanCompany, New York,

lengthwise direction.

According to, this prior art suggestion, the Sepro bag was filled withan ordinary aerosol foam formulation, including the usual propellant, anadditional propellant being used in the can outside of the bag as adriving force to dispense the formulation. This dispensing propellanthad a vapor pressure of at least 15 psi greater than that of thepropellant system in the emulsion, the latter, therefore, beingcompressed within the bellows-type Sepro bag so that the latter did notcontain a head space or void. In this way it was hoped to dispense aproduct of uniform density throughout the life of the package.

All ordinary aerosol foam formulations require agitation by shaking thepackage just prior to use, this being possible because in the usualpackage there is a head space or vapor space abovethe product containingthe liquified compressed gas propellant. Shaking causes the product toslosh up and down in this head space. In the case of the above prior artproposal, there was no head space and other agitating means wererequired.

Therefore, a steel ball such as is conventionally used in aerosol paintdispensing packages, was included with the formulation in the Sepr"container; but lacking the paint packages head space, the ball couldmove to effect agitation only by plowing through the solid mass ofrather highly compressed foam formulation. Consequently, effectiveagitation of the formulation in the Sepro container, by normal manualshaking such as commonly exerted by the user of such a package, wasnever suggested as a possibility. To obtain adequate motion of the steelball, vigorous shaking was suggested, without further explanation.

No attempt was ever made to commercialize the above proposal insofar asis known.

SUMMARY OF THE INVENTION With the foregoing in mind, one of the objectsof the present invention is to provide an aerosol package containing aproduct in which a liquified compressed gas is intimately dispersed ordissolved and which will smoothly extrude or eject the product with anegligible or greatly reduced overrun and without appreciable change inthe density of the product, particularly when the package isintermittently used over a prolonged time period. In the event of apackage containing a product in which a liquified or unliquifiedcompressed gas is intimately dispersed or dissolved so as to involve thesame kind of problems, another object is to achieve the same results asjust described, in such instances also.

According to the invention, an aerosol package of the so-calleddiaphragm system type is used. In the prior art such a package has beenused only to separate two incompatible formulations, or to separate aproduct from the propellant providing the extruding pressure. This typeof package comprises a rigid outer container, such as the usual aerosolmetal can, inside of which is located a collapsible flexible containerwhich receives the vapor pressure of the propellant and thereby theproduct discharging force.

However, in the case of the present invention, the collapsible flexiblecontainer is charged with the liquid product in which the liquifiedcompressed gas is intimately dispersed or dissolved for the purpose ofconverting the product into a desired physical form when discharged intothe atmosphere. Further, a liquified compressed gas propellant ischarged in this cans rigid container between the latters inside and theoutside of the collapsible flexible container. This second propellant isselected as one having a vapor pressure substantially greater than thatprovided by the products liquified gas as it is intimately dispersed ordissolved in the product. Preferably this second propellant should havea vapor pressure at least about 5 pounds per square inch gauge higher,plus the collapse pressure of the flexible container, than the vaporpressure imparted to the product by its liquified gas as it is widelydispersed or dissolved in the product.

The effect of the invention is to always maintain the liquified gas inthe product in its liquid phase during the discharge of this productthrough the aerosol package valve when there would otherwise be apressure drop resulting in the products liquified gas converting to itsvapor phase within the product and producing gas bubbles which have nowbeen found to result both in undesirably high overruns and ejectedproduct density changes.

Preferably the collapsible flexible container is one having the lowestpossible collapse resistance pressure compatible with impermeability. Insuch an instance, the flexible container collapses and may block off thevalve inlet, a standpipe ordinarily not being indicated for use withthis invention because the flexible container has no air space since itis maintained under compression or pressure by the vapor pressure of thepropellant on its outside between it and the rigid containers interior.The present invention solves this blockage problem by the use of astandpipe flexible enough to deform and prevent damage to the collapsingflexible container and which has a series of openings through its wallextending along its length. With this arrangement, it becomes impossiblefor the collapsing flexible container to block off the discharge of itscontents.

Using the above flexible container of low collapse resistance and whichcollapses in all directions, it becomes possible to shake a formulationwithin the flexible container by shaking the entire package in thenormal manner that any aerosol foam formulation package is shaken whenhaving the usual head space above the formulation within the rigidcontainer or can. Having equal pressures on both the inside .and outsideof the containers wall, the container is free to move within the rigidcontainer without restraint. Being entirely flexible, preferably to themaximum degree possible, the container or bag can flop about freelywithin the rigid container when the latter is shaken in the normalmanner.

In addition to the advantages described, a package made according to theinvention can be operated in any position, including a completelyinverted position. Vertical rotation in the axial plane of the packagethrough 360 does not interfere with the discharge ofthe pack- I agecontents in any way.

DESCRIPTION OF THE DRAWINGS DETAILED DESCRIPTION OF THE DRAWINGS In FIG.1, the rigid container is shown as a commercially available aerosolpackage metal can having a cylindrical wall 1, a domed top 2, and aninternally convex bottom 3 and a mouth 4, the internal collapsibleflexible container 5 being in the form of a very thinwalledfluid-impervious bag 5 having its wall space only slightly inwardly fromthe can wall 1 and bottom 3, and with its upper peripheral edge clampedfluid-tightly by the mechanical seam 6 of the can. Such a can ismanufactured currently by the American Can Company and sold under thetrademark STERIGUARD. The collapsible flexible container 5 has acollapse pressure of not more than about 2 pounds per square inch gauge.The mouth 4 of the can is closed by a cup 7 mounting an aerosoldispensing valve 8 having an actuating and dispensing tubular stem 10and an inlet 11, the latter being provided with the flexible standpipe12 having a series of either holes 13 or notches 13a, or both, extendingthroughout its length.

An oil-in-water emulsion'5a in which a liquified compressed gas iswidely distributed, and to some extent dissolved, completely fills thecollapsible container 5; and a liquified compressed gas propellant 9 isinserted in the can by needle pentration of a rubber grommet 9a in thebottom 3. There is only a low level of this liquid propellant 9 in thecan, but its vapor pressure extends throughout all of the space betweenthe can and the flexible container 5, as is indicated by dots in FIG. 1.The vapor pressure of the propellant 9 on the collapsible flexiblecontainer 5 keeps the product 5a under compression or pressure so thatthe latter completely fills the container 5 and the can top 2, whilekeeping the product 5a under adequate compression or pressure to preventany of its components from converting to gas or vapor phase. Also, thisvapor pressure applies extrusion or discharge force to the product.

Depending on the formulation, the vapor pressure of 20 pressure of thepropellant 9 should be high enough to keep the product 5a under adequatepressure or compression, even when the valve is opened when there wouldbe; a pressure drop in prior art packages, to prevent any portion oftheproduct 5a' from converting to its vapor or gas phase.

This new package has the great advantage that the the cans No. 3 and No.4 such as would correspond to the propellant 9 in F IG. 1. In otherwords, cans No. l and No. 2 were made as shown by FIG. 1; and cans No. 3and No. 4 were made up in substantial accord 5 with the prior art,excepting for the flexible container 5 pressed gas propellant; namely,isobutane having a vapor pressure of 31 pounds per square inch gauge at70 lnsashs ths sans N9: 1.. an N .2. i accordance with the presentinvention, 16.5 grams of a higher vapor pressure liquified compressedgas propellant, namely Propellant 12 (sold under the trademark Freon12), having a vapor pressure of 72 lbs. per square inch gauge at 70F.,was introduced between the cans inside and the outside of the flexiblecontainer. All'four cans were stored for 24 hours at 70F. and thereafterwere uniformly shaken and extruded in gram increments every 24 hoursuntil the cans could no longer effectively eject their contents.

The Propellant 12 was injected in cans No. l and No. 2 through the usualrubber grommet 9a in the cans without the use of a vacuum chamber, sosome air was included with the propellant in these instances.

After each 20 gram extrusion, a portion of each extrusion was dischargedinto a 50 cc container to permit a density determination in the usualmanner, this being done as to all four cans.

Under the foregoing conditions, the following results ,y ,ts.. 2 a n 2Present invention Prior art Can No. 1 Can No, 2 Can No. 3 Can No. 4

Grams Dens. Dens. Dens. Dens.

extruded p.s.i.g G/cc p.s.i.g. G/cc p.s.i.g -G/cc p.s.i.g. G/ccdischarge product is of uniform consistency and density throughout thelife of the package, even when used intermittentl y during a long timeperiod, and substantially all of the product 5a is finally ejected sothat practical'ly none remains in the package ultimately. The package isoperative even if inverted.

To demonstrate the above advantage of consistent uniform density, twocans or packages, marked No. 1

and No. 2, were made up substantially like that illussolid throughoutits length in the conventional fashion instead .of being perforated asshown in the case of the standpipe 12. Further, no propellant wasinjected into It can be seen from the above that in the case of thepresent invention, represented by cans No. 1 and No. 2, there waspractically no change in the density of the product ejected during each24-hourperiod. The pressure in pounds per square inch gauge droppedbecause the Propellant 12 included some air, as previously mentioned, sothat the effect of this compressed but unliquified gas exerted itsinfluence. However, throughout the test the vapor pressure of thePropellant 12 was adequate to keep the gasified soap formulationpropellant fromconverting to vapor or gas phase; as to any or all of itscomponents, so this pressure drop did not affect the uniform foamdensity of the product obtained throughout the test.

The importance of the above is highlighted by reference to the test dataof the prior art cans No. 3 and No.

4. Here the density of the extrudedproduct increased from 0.08 to 0.242and 0.262, respectively, while the can package pressure reduced from 34to 18 pounds per square inch gauge in the case of can No. 3 and from t35 to 17 in the caseof can No. 4. These effects resulted from the factthat as the contents of the prior art cans No. 3 and No. 4 reduced, moreand more of the propellant vapor was lost because of its converting toits vapor or gas phase in the can, the density of the ejected productcorrespondingly increasing throughout the life of the test. In the caseof a shaving cream formulation, for example, this increase in densitywould result in the cream becoming runnier and runnier, and finally inthe characteristic sputtering experienced with prior art packages and,consequently, a substantial amount of the product remaining in the canas waste.

In the case of a haircoloring foam formulation in codispensing haircoloring aerosol packages, this density increase would result in vastmisproportioning in the I foam dye formulation relative to the liquidperoxide solution simultaneously ejected.

As indicated by the tabulated data, the present invention avoids all ofthese. problems because of the uniform density of the product extrudedthroughout the life of the package.

Macroscopic examination of the foam 's product from the cans using theinvention and the prior art cans, at 20x magnification, clearly showedthat in the discharge of the present invention, there were no large gasbubbles, whereas such gas bubbles were very obvious in the case of thedischarge from the prior art cans. These gas bubbles formed when thedispensing valvewas operated and the product propelled solely by thepropellant distributed-or dissolved in the product, it appearing thatthe pressure drop occurring when the valve was opened permitted theproducts gas to convert to its vapor or gaseous phase and formrelatively large gas bubbles, resulting in the very large density changein the intermittently discharged product, These gas bubbles of necessitychanged the density and thus altered its physical characteristics fromthat desired, and resulted in excessive loss of the propellant gas witha consequent large pressure reduction in the package preventing completedischarge of all of the contents of the package. In the case of thepresent invention a smooth discharge of constant density of foamthroughout the life of the tests was obtained; the discharged producthad a uniform density and maintained a predeterminable physicalcharacteristic in every way insofar as was detectable. There was noWaste possible, as an inherent a advantage.

It is to be understood that a liquified compressed gas propellant, whendissolved in the liquid product, results in a lowered vapor pressureaccording to the law of partial pressures. When widely dispersed in theproduct, as in the case of an oil-in-water emulsion, the vapor pressurethat results substantially corresponds to that of the propellant,excepting that to the degree the propellant might go into solution evenin such instances. It follows, therefore, that in some instances exactlythe same propellant may be dissolved in the liquid product more or less,with a resulting overall lower vapor pressure, as is also used betweenthe flexible container and the can where the propellant maintains itsfull inherent vapor pressure.

Normally the propellant dispersed or dissolved in the product to bedischarged would be liquified com- 8. pressed gas having a vaporpressure ranging from about 3 to about 40 pounds per square inch gauge,while the vapor pressure of the propellant on the outside of theflexible container 5 should be a liquified compressed gas having a vaporpressure at least about 5 pounds per square inch gauge higher than. thevapor pressure of the gas in the product as or while the latter isintimately dispersed or dissolved therein, plus, of course, the collapsepressure of the flexible container itself. This collapse pressure mustbe deducted from the vapor pressure of the propellant outside of theflexible container when calculating the higher pressure required.

Because of safety regulations in general, the internal pressure of anaerosol package is limited, and, therefore, it is not believed that thecollapse pressure of the collapsible flexible container 5, or its'counterpart, should exceed 20 pounds per square inch gauge. Preferably,the collapse pressure of this flexible container should be kept as smallas possible consistent with reliable impermeability and freedom fromdamange such as when the package is shaken.

Concerning shaking of the package, it is to be understood that mostpackages containing an emulsion or the like require shaking just priorto use. With the present invention the flexible container 5, or itscounterpart or equivalent, is in equilibrium so far as fluid pressure isconcerned. The vapor pressure of the propellant 9, indicated by dots, isapplied throughout the outside of the flexible container 5 and theproduct 50 also in this container 5 exists under a corresponding fluidpressure regardless of its own vapor pressure. Therefore, the container5 is capable of flopping about within the can during shaking whenrequired and thus agitates its contents.

As shown by the drawings, the flexible container 5 is a bag having athin wall which for its major portion is tubular and cylindrical, thecan, of course, also having a cylindrical wall. The bag wall is spacedonly slightly inwardly from the inside of the cans wall and the bag hasa bottom wall that is spaced only a little above the relatively lowlevel of the propellant 9. The vapor pres-' sure between the bag and thecan inherently produces a space between the bag and can walls when thepackage is made up, in the event the two walls were initially in contactwith each other. This space forms what might be called the equivalent ofthe head space or vapor space above the formulation in the prior artcommercial foam dispensing packages.

Because the propellant 9 is confined against any possible loss, there isno loss of this propellant as there is in prior art packages where thepropellant must function not only to modify the discharge product butalso to effect its discharge. The production of the previously describedgas or vapor bubbles results in a constant loss of this propellant witha consequent density change and low value of overrun in the case ofprior art packages. Because these prior art packages have a vapor spaceabove the liquid product they cannot be operated except in a more orless upright position, whereas with the present invention there is nosuch limitation in the operating position.

FIGS. 2 and 3 illustrate the principles of this invention applied to anaerosol codispensing package, and because of the exacting demands of ahair coloring package that can be used intermittently over a prolongedtime period without change in its coloring effect, which is beyond theability of the prior art, such a package is chosen as an example.

Now having reference to FIGS. 2 and 3 of the drawings, a metal, andtherefore relatively rigid, can is made of sheet metal and has acylindrical side wall 1a, a domed top 2a and a concave bottom 3a, thetop having avalvemounting cup opening 4a which, according to today'sstandards, would usually be one inch in diameter/A flexible container 5ais inside of the can and is in the form of an open-topped bag having itstop periphery clamped in a mechanical seam 6a between the side wall 1aand the top 2a of the can. The cans top opening 4a is closed by aso-called one-inch valve cup 7a in which an aerosol codispensing valve8a is mounted.

The container 5a contains the liquid or fluid product including theliquified gas, this product being indicated in the drawings at 5a". Inthis instance it would be an oil-in-water emulsion containing the haircoloring and in 'which the liquified compressed gas is intimatelydistributed or dissolved. The valve mounting cup 7a is applied to thecans opening 4a after the container 5 is filled with the gasifiedproduct. The liquified compressed gas propellant 9a is injected in thecan through the rubber plug or grommet 9a. It is thispropellant9a thathas the substantially greater vapor pressure that does the liquified gasas it is distributed or dissolved in the product in the container- Sa,at least at usual room V temperatures. The container 5a has adequateflexibility to'transmit substantially all of the fluid pressure exertedby the vapor pressure of the flu'idpropellant 9a to the product insideof the container 5a.

The valve 8a' is of the nonnally'closed type and is opened by fingerpressure on its tubular dispensing stem 10a, the product in thecontainer 5a entering the valve 8a through an inlet nipple 11a. Openingof the valve to dispense the product results in the vapor pressure ofthe propellant 9a extruding the product through the stem 10a with theproduct functioning as intended in the atmosphere; its liquifiedgas,upon extruding, converting to its gaseous phase. By choosing as thepropellant 9a a liquified compressed gas having an adequately. highvapor pressure, this gas in the product is prevented from converting toits vapor phase within the container 5a, resulting'in a smooth extrusionof the product through the stem 10a with all of the previously describedadvantages.

his to be understood. that the quantity of propellant 9a in the can mustbe enough to apply the desired high vapor pressure continuously to theoutside of the con tainer 5a until all of the product in the container5a is extruded.

The container 5a must not only be impervious to the liquified gaspropellant and to the product in the container 5a which includes thatliquified gas, but also it must be as flexible as possible. Aspreviously noted, aerosol cans are commercially available having thegeneral configuration shown by the drawings and with a flexible bag madein the can, as indicated by the drawings; there are manufacturedcurrently by the American Can Company and sold under the trademarkSTERI-GUARD, also previously noted. The containers in these canscorresponding to the container 5a have adequate imperviousness to fluidsand a collapsible pressure of less than 2 pounds per square inch gauge.In the practical sense, substantially all of the vapor pressure exertedby the vapor of the liquified gas propellant 9a is applied to thecontents of the flexible container which corresponds to that shown at 5ain the drawings. These cans are normally charged with the liquified gaspropellant through their bottoms.

In practicing the present invention, it was found that the greatflexibility of the container 5a introduced the problem that as thiscontainer collapsed as the product was extruded, the container blockedor closed the inlet 11a to the valve 8a, as previously noted. However,when the flexible tube, shown at 12a in the drawings, is connected tothe inlet nipple 11a of the dispensing valve, and is provided with alengthwise series of openings, such as the holes or notches 13a and 13a,this trouble is corrected, even if the container 50 collapses inwardlyand possibly actually folds around the tube 12a, and the tube 12a itselfpossible became contorted. Always one or another of the openings remaineffective to provide a passage for the product from the container 5a sothat a positive extrusion of the product always results. More than oneseries of the openings may be used with one series circumferentiallydisplaced relative to the other, or the lengthwise series of notches maybe used.

The valve 8a is of the codispensing type, and therefore, has a secondinlet 14 with which a second flexible container 15 is connected. Thissecond container is located inside of the containerSa and receives thefluid pressure from the product in the container 5a and to which thevapor pressure created by the liquified gas propellant 9a is appliedthrough the flexible container 5a. This pressure applied to the outsideof the container 15 extrudes its contents also when the valve 8a isoperated.

Assuming that the codispensing valve 8a is correctly designed toproperly-proportion the two extruded products, these proportions will bemaintained throughout all or substantially all the life of the packagebecause the extruded product always has substantially the same densityand other predetermined characteristics, as previously noted.

As contrasted to the current one-shot package of aerosol hair coloring,required for home or personal use by the limitations of the prior art,the illustrated package may be made large enough to provide amultiplicity of one-shot applications and can be used to touch-up thehair after the initial application of coloring, for example, because thecoloring effect is unchanging due to the consistent characteristics ofthe product 5a" when extruded.

In this case of hair coloring, as an example,-the hiar coloringformulation contains the liquified compressed gas to produce a coloringfoam while the inside container 15 contains a peroxide solution liquid,indicated at 15a, which normally does not contain a gas propellant.Therefore, this container 15 may be made of material which, althoughflexible, is stiff enough to permit its manipulation during assembly ofthe package as described hereinafter; However, its collapse pressureshould not be so great as to prevent reliable extrusion of its contentsunder the fluid pressure applied to it by the contents of the container5a. The tube 12a is made of material which is not excessively resistantto bending or other deformation such as might result in damage to thecollapsing container 5a.

To demonstrate the practicality of the present invention, packages havebeen made using the principles disclosed by FIG. 2 35 grams of a 10percent water solution of sodium thiosulfate (Na S O was placed in theinner containers which corresponded to the container 15. In the outercontainer 5a, grams of a soap solution was placed, this solution beingoutlined by the text Cosmetics Science and Technology. published byInterscience Publishers, Inc., New York, 1957 on page 832, Formula No.16. The soap solution included 6.7 grams of isobutane having a vaporpressure at room temperature (approximately 70F.) of about 31 pounds persquare inch gauge l o grams of Propellant 12 (CCl F were placed in thecans corresponding to the illustrated can between the inside of the cansand the outsides of the containers a. This liquified gas propellant,when the packages were at room temperature, provided a vapor pressure ofabout 72 pounds per square inch gauge. This liquified gas is sold underthe trademark FREON 12," are previously mentioned. The valves used wereaccurately operating codispensing valves designed to dispense at a 4:1ratio between the soap or foam solution product and the non-foamingsolution in the containers corresponding to the container 15.

To test the operation, a piece of aluminum was placed on a balance andtared for 100 grams net. The product from the package was partiallyextruded on one end of the aluminum plate initially and the lastportions of the foaming product on the other end of the plate. In thismanner it was possible to analyze the percent of sodium thiosulfate inthe initial and final portions of the extruded product. Three of suchpackages were tested in the above manner with the results shown below:

Cans

- 1 2 3 3b Na,S,O;, initially 1.74% l.82% 1.94% Last portion of 100grams 1.83% l.80% 2.04%

The above noted differences between the first and last portions of the,extruded product are in each instance well within the demands ofaccuracy in the case of a foaming hair coloring composition containingthe usual liquified gas, and the non-foaming perioxide solution whichmust be mixed with this product during the dispensing action. Thisaccuracy was obtained because the foaming product did not experience theprevious troubles, the liquified gas remaining in the product widely andintimately dispersed in liquid form until dispensed to the atmospherethrough the dispensing valves.

It is to be understood that the foaming or other gasified product maycontain any liquified or unliquified compressed gas which can becontained by the product in solution or dispersed from and if itpresents the problems described hereinabove, as exemplified byoil-inwater emulsions in which a liquified compressed gas is widely andintimately dispersed, providing this gas does not provide an excessivevapor pressure at room temperature and keeping in mind that it mustprovide a lower vapor pressure than that of the liquified gaspropellant. The vapor pressure of the latter must be higher so that itcan perform its function of preventing the gasified product fromconverting to its vapor phase. At the same time the liquified gaspropellant compressing the product must have a vapor pressure low enoughto meet can safety and shipping requirements.

It is believed reasonable to state that the gas in the gasified liquidproduct, which may include various components and even two or moreliquified or compressed gases, should have a vapor pressure ranging from3 to 40 pounds per square inch gauge at 70F. The liquidifed gas actingas the compressor and propellant,

and this may include two or more liquified gases, should have a vaporpressure at least 5 pounds per square inch gauge at 70F, plus thecollapse resistance of the flexible container, in excess of theparticular vapor pressure of the liquified gas or gases as they aredispersed or in solution with the gasified liquid product.

in this container. Enough of this liquid gas propellant should be usedso that until all or substantially all of the gasified product isextruded, this pressure differential continues.

In the previously notedtests of these cans, the flexible containerscorresponding to the container 5a had a collapse pressure of less than 2pounds per square inch gauge fluid pressure. Therefore, the reduction itmade in the pressure applied to the gasified product by the liquifiedgas propellant was negligible. Obviously the use of a stiffer containerwould require a higher pressure differential between the liquified gaspropellant vapor pressure and the vapor pressure of the liquified gas inthe gasified product, keeping in mind that if in solution with thegasified liquid or liquids, the vapor pressure may be lowered.

A codispensing package could be made in accordance with the principlesof this invention with a can containing two separate containers havingthe same degree of flexibility as the container 50, and thesecould bearranged side-by-side in the can (not shown). However, there is atpresent no commercially available container of this type or one that iscapable of being handled by present-day, commercial, necessarilyhighproduction packaging equipment With such two or more separatecontainers side-by-side, the package could be made to contain equalproportions of the fluid components if desired.

Recognizing the above, the package shown by the drawings incorporates ina generally accurate manner the commercially available can having theflexible bag 50 incorporated in its construction by the canmanufacturer. As previously indicated, the diameter of the hole or mouth4a in the top of the can has the standard oneinch diameter. Duringassembly of the package the container 5a may be charged with thegasified product through this hole by cold filling. The container 15 isinserted through this one-inch hole 4a, being held by the fingers ofautomatic machinery by a rib 16 formed on the neck of the container 15to prevent the latter from dropping completely into the can. Thecontainer 15 is then filled, the inlet 14 of the valve 8a is inserted inits neck with a press fit or otherwise so as to be retained, and thevalve assembly 8a has its mounting cup 7a crimped around the mouth ofthe can. The correct amount of liquified gas propellant is chargedthrough the rubber grommet 9a in the bottom of the can and the packagethus is substantially completed. The above means that ordinarily thecontainer 15 must have a diameter of less than one inch to permit itsinsertion through the hole or mouth 4a. In the drawings the mouthdiameter is indicated at X, it being possible that -ble.

with its opposite ends 17 having a very slightly smaller diameter X thanthe diameter of the. top opening of the can. Between these extreme endportions. 17, the container has longitudinally extending, radiallyoutwardly projecting ribs or'bulges 18, each of substantial peripheralextent. As shown by the drawings, these ribs or outwardly projectingflutes provide the container with a diameter indicated at Y which issubstantially greater than the diameter X. Therefore, when the containeris in the package, the container 15 has a substantially greatervolumetric capacity than if. it were made with the typical prior artcylindrical shape with a maximum diameter of slightly less than one inchas required for its passage through the cans top opening.

As shown by FIG. 3, these outwardly extending bulges or ribs 18 deflectinwardly duringinsertion of the container 15 in the can. The containermay be made of a plastic that is suitably inert to the liquids andfluidsit must contact, and this plastic should be of such a characterand thickness as to provide the container with'the rigidity necessary topermit its being handled by the automatic machinery, while at the sametime being flexible enough, as previously described, to result indispensing of the product in the package. The container may be blowmolded orotherwise formed with either the specific .coritour illustratedor otherwise to permit'insertion' of its lower end 17in the cans mouthand by pressure forced to be pressed completely in the can,

After insertion in the cans mouth, as indicated by FlG.'3, thecontainers rib 16 may be or continues to be engaged by the automaticmachinery fingers. The top one of the cylindrical portions 17 of thecontainer permits the container to'be held with its top at or above thecans mouth during filling ofth'e container 15. It is to'be understoodthat 'thecontainer' 15 may have any be a compressed unliq-uitied gas,but because of its decreasing pressure with 'expansion and the limitedspace available for its use, a liquified gas is definitely prefera- Asexplained above, when the present invention is applied to a codispensinghair coloring package, the two components are extruded to provide exactproportioning between them even when the package is oper-.

ated intermittently over a prolonged time period. However, since thepropellant between the flexible container andthe rigid container or canis preferably a liqluified compressed gas, it follows that the rate ofdisperatures in the case of the present invention, it is possible toestablish tabulated data showing the different time periods of dischargefor different temperatures required to always extrude the same amount ofthe properly proportioned components.

For example, if with a particular hair coloring formulation and peroxidesolution, a ten second discharge at provides a predetermined coloringeffect intended to be produced by the user of the package, the tabulateddata might show that to produce the same effect a twelve seconddischarge at 68 and an eight second discharge at would be required toproduce the same exact hair coloring effect. The same principle would beapplied to minor touch-up hair applications, only the time periods wouldbe shorter. This tabulated data could be, for example, applied to theoutside of the can so that the user, by reference to a thermometer and atiming device, could always produce the same coloring results. The timeperiods suggested are, of course, purely exemplary and may vary widelywith differing formulations and with differing propellants.

What is claimed is:

1. An aerosol package comprising a substantially rigid container havinga dispensing valve, a collapsible containerinside of said rigidcontainer and containing a'product'including liquified compressed gas,said containers defining a space therebetween, said rigid containerhaving a dispensing valve connected with the inside of said flexiblecontainer for dispensing said product to the atmosphere, and gaseousmeans for maintaining vapor pressure in said space and including avolume of liquified compressed gas propellant having avolume-substantially less than that of said space, said vapor'pressurebeing 'sufficient to prevent the formation of a head space within saidflexible container; wherein the improvement comprises said flexiblecontainer being in the form of a bag that is flexibly movable andcollapsible in all directions and having a wall with a thinness andshape rendering it collapsible and displaceable in all directionstransverse to its surfaces, all pressures on the opposite sides of saidbag corresponding to each other so that said flexible container iscapable of flopping about within said space to shake said product whensaid rigid container is shaken, and in which the vapor pressure of saidgaseous means is sufficient to prevent said liquified compressed gas insaid product converting to gas or vapor phase when said product isdispensed to the atmosphere via said valve, the vapor pressure of saidproducts gas being sufficient to by its substantially instantaneousflash evaporation alter the physical form of said product when dispensedto the atmosphere; saidpackage including at least a second collapsibleflexible container inside of said firstnamed flexible container, saidvalve being a codispensing valve having at least two inlets to whichsaid flexible containers are repsectively connected, said secondflexible container containing a liquid for mixing with said product insaid first-named flexible container by operation of said valve, saidliquified gas propellant applying fluid pressure to said second flexiblecontainer through said first-named flexible container and said producttherein and upon operation of said valve also extruding said liquid insaid second flexible container.

2. The package of claim I in which the vapor pressure of said liquifledgas in said product ranges from about 3 to about 40 pounds per squareinch gauge, and the vapor pressure of said liquified gas propellant isat least about pounds per square inch higher than the vapor pressure onsaid gas intimately dispersed or dissolved in said product in saidfirst-named flexible container, plus the collapsible resistance of thiscontainer, when said package has a temperature of approximately 70F.

3. The package of claim 2 in which said first-named flexible containercollapses under an external pressure of less than approximately 20pounds per square inch gauge.

4. The package of claim 3 including a flexible tube by which saidfirst-named flexible container is connected to one of said valvesinlets, said tube extending from said valve a substantial distancewithin said first-named flexible container and having a lengthwiseseries of openings in its wall, said tube being outside of said sec- 0ndflexible container, said first-named flexible container collapsingextensively as said product is extruded therefrom and said openingsprevent blockage of said tube by the collapsing wall of said first-namedcontainer.

5. The package of claim 1 in which said rigid container has an openingin its top of predetermined diameter and said second container has alarger diameter throughout a substantial extent of its length and isradially collapsible to a degree permitting its insertion through saidopening and which subsequently expands for filling with said liquid formixing with said product.

6. The package of claim 5 in which said second container has endportions of slightly smaller diameter than said opening.

1. An aerosol package comprising a substantially rigid container havinga dispensing valve, a collapsible container inside of said rigidcontainer and containing a product including liquified compressed gas,said containers defining a space therebetween, said rigid containerhaving a dispensing valve connected with the inside of said flexiblecontainer for dispensing said product to the atmosphere, and gaseousmeans for maintaining vapor pressure in said space and including avolume of liquified compressed gas propellant havinG a volumesubstantially less than that of said space, said vapor pressure beingsufficient to prevent the formation of a head space within said flexiblecontainer; wherein the improvement comprises said flexible containerbeing in the form of a bag that is flexibly movable and collapsible inall directions and having a wall with a thinness and shape rendering itcollapsible and displaceable in all directions transverse to itssurfaces, all pressures on the opposite sides of said bag correspondingto each other so that said flexible container is capable of floppingabout within said space to shake said product when said rigid containeris shaken, and in which the vapor pressure of said gaseous means issufficient to prevent said liquified compressed gas in said productconverting to gas or vapor phase when said product is dispensed to theatmosphere via said valve, the vapor pressure of said product''s gasbeing sufficient to by its substantially instantaneous flash evaporationalter the physical form of said product when dispensed to theatmosphere; said package including at least a second collapsibleflexible container inside of said first-named flexible container, saidvalve being a codispensing valve having at least two inlets to whichsaid flexible containers are repsectively connected, said secondflexible container containing a liquid for mixing with said product insaid first-named flexible container by operation of said valve, saidliquified gas propellant applying fluid pressure to said second flexiblecontainer through said first-named flexible container and said producttherein and upon operation of said valve also extruding said liquid insaid second flexible container.
 2. The package of claim 1 in which thevapor pressure of said liquified gas in said product ranges from about 3to about 40 pounds per square inch gauge, and the vapor pressure of saidliquified gas propellant is at least about 5 pounds per square inchhigher than the vapor pressure on said gas intimately dispersed ordissolved in said product in said first-named flexible container, plusthe collapsible resistance of this container, when said package has atemperature of approximately 70*F.
 3. The package of claim 2 in whichsaid first-named flexible container collapses under an external pressureof less than approximately 20 pounds per square inch gauge.
 4. Thepackage of claim 3 including a flexible tube by which said first-namedflexible container is connected to one of said valve''s inlets, saidtube extending from said valve a substantial distance within saidfirst-named flexible container and having a lengthwise series ofopenings in its wall, said tube being outside of said second flexiblecontainer, said first-named flexible container collapsing extensively assaid product is extruded therefrom and said openings prevent blockage ofsaid tube by the collapsing wall of said first-named container.
 5. Thepackage of claim 1 in which said rigid container has an opening in itstop of predetermined diameter and said second container has a largerdiameter throughout a substantial extent of its length and is radiallycollapsible to a degree permitting its insertion through said openingand which subsequently expands for filling with said liquid for mixingwith said product.
 6. The package of claim 5 in which said secondcontainer has end portions of slightly smaller diameter than saidopening.